Rotor-periphery and adjacent shredder-ring structure for food waste disposer



Jan. 27, 1959 J. s. WILLIAMSON 2, 7

ROTOR-PERIPHERY AND ADJACENT SHREDDER-RING STRUCTURE FOR FOOD WASTE DISPOSER Filed May 9, 1955 2 Sheets-Sheet 1- INVENTOR JOHN S.W|LL|AM$ON ATTORNEY Jan. 27, 1959 J. s. WILLIAMSON 7 5 ROTOR-PERIPHERY AND ADJACENT SHREDDER-RING STRUCTURE FOR FOOD WASTE DISPOSER Filed May 9, 1955 2 Sheets-Sheet 2 4 FIG] 5 26 27% FIG.|O.

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r'' '3' mm ji F|G.ll H6 4 INVENTOR JOHN S WILLIAMSON ATTORNEY ROTOR-PERIPHERY AND ADJACENT SHRED- DER-RING STRUCTURE FOR FOOD WASTE DEPQSER I Application May 9, 1955, Serial No. 506,860 4 Claims, ((1241-260) This invention relates toa food waste disposer in which food waste is ground into fine particles to be carried away by a stream of water into waste pipes.

An object of the invention is to provide an improved disposer.

A particular object is to prevent accumulation of material in the gap between the cooperating rotating and stationary elements. When a material such as corn husks, string, cloth tea bags or other fibrous material is admitted to a disposer of a construction previously used, it has been found that the fibers tend to accumulate and become wedged in the gap between the periphery of the rotor and the inner surface of the shredding sleeve. As the accumulation of material continues, the friction on the rotor increases the load on the motor, resulting in either frequent tripping of the motor protector or failure of the motor to start.

In accordance with the present invention, the rotor is rates Patent formed with one or more recesses of suitable form in its periphery. The recess should extend upwardly at least as high as the lowest part of the top surface of the rotor adjacent the periphery. It should be of sufiicient width, i. e., in circumferential direction. The recess is preferably of increasing width in downward direction. The recess should not provide an opening in the top surface of the rotor that is of greater width than the size of particle to which it is desired to reduce the material. When such a recess is placed directly below an impelling vane or projection on the top surface, there is no opening in the top surface.

These and other objects are effected by the invention as will be apparent from the following description taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is an elevational view, with parts in section, of a food waste disposer incorporating the present invention;

Fig. 2 is a fragmentary perspective view of the shredding sleeve;

Fig. 3 is a fragmentary vertical section, on an enlarged scale, of the first embodiment shown in Fig. 1, which is the preferred or commercial embodiment;

Fig. 4 is a plan view of the rotor of Fig. 1, and also showing a fragmentary portion of the shredding sleeve and the casing;

Fig. 5 is a bottom plan view of of the rotor shown in Fig. 4;

Fig. 6 is an elevation of a portion of the rotor of Fig. 4 having an inclined slot in the top surface, this figure and the remaining figures being on a larger scale than Fig. 4 and 5; r

Fig. 7 is a sectional view, taken on the line VII.VII of Fig. 4 and showing the inclined slot of Fig. 6;

Fig. 8 is an elevation of a portion of the rotor of Fig. 4 that includes one of the impelling vanes and a recess thereunder;

Fig. 9 is an elevation of a portion of the rotor of Fig. 4, showing the other form of recess in said rotor;

a fragmentary portion between the grinding chamber Fig. 10 is a section taken on the line X--X of Fig. 4 and showing the recess of. Fig. 9;

Fig. 11 is a side elevational view similar to Fig. 8 but showing a second embodiment of rotor which has a modified form of recess beneath an impelling vane;

Fig. 12 is a fragmentary view, partially in elevation and partially in section, showing the, rotor of the second embodiment;

Fig. 13 is a bottom plan view of the portion of the rotor shown in Fig. 12;

Fig. 14 is a fragmentary elevational view showing one of the recesses of the second embodiment that is not beneath an impelling vane;

Fig. 15 is an elevational view, similar to Figs. 8 and 11, of a third embodiment of the rotor showing still another form of recess beneath an impelling vane;

Fig. 16 is a fragmentary view, partially in elevation and partially in section, of the rotor of the third embodiment; and l Fig. 17 is a bottom plan view of the portion of the rotor shown in Fig. 16.

Referring to the drawings in detail, and first to Fig. 1, the food waste disposer comprises a casing 10 which incorporates a grinding chamber 11, a discharge chamber 12 and a motor chamber 13. The grinding chamber 11 is open at the top for admission of material to be comminuted and also for admission of a stream of water for carrying away the comminuted particles.

A disc-like rotor or impeller 14, often referred to as a flywheel, is disposed horizontally to form a partition and the discharge chamber, more particularly to form the bottom of the grinding chamber. The rotor is mounted on the upper end of the vertical shaft of a motor in the chamber 13, which motor is preferably operable to drive the rotor in either direction of rotation. The vertical motor shaft extends through and is positioned by a bearing structure 15.

A shredding sleeve or liner 16, commonly referred to as a shredder, is disposed within the casing and encircles the lower portion of the grinding or shredding chamber 11 and also the top surface of the rotor. It is preferably clamped between two parts of the casing that are bolted together. The shredding sleeve is of generally cylindrical or tubular form and is preferably formed by casting. On its inner surface adjacent its lower edge, it is formed with an annular series of teeth 17, which are spaced from each other by strainer slots 18 formed therebetween. The strainer slots 18 are of a width to permit free passage of particles of the size to which it is desired to reduce the material. In the preferred commercial embodiment, these slots are fwide at the bottom. They taper slightly and are therefore slightly narrower, about at the top.

The shredding sleeve is also formed with a suitable number, preferably three, of projections 19 disposed approximately equidistantly around the circumference. Each of these projections extends upwardly from the row of teeth. Each side is preferably of a stepped configuration, as shown in Fig. 2, and presents sharp cutting edges and corners to the material to be comminuted. The inner surfaces of the teeth 17 and the projections 19 are disposed on a common radius. The projections 19 are more fully described and claimed in application Serial 3 of the top surface of the rotor is disposed. The outer ends of the vanes are preferably disposed on the same diameter as the periphery of the rotor, although they may be slightly inclined upwardly and inwardly to facilitate casting the rotor. The rotor is formed with a plurality of openings 22 which serve principally to permit flow of water therethrough when the motor is not energized. The rotor is also formed in its top surface with slots 23, the bottom surfaces of which are inclined downwardly toward the periphery, as shown in Fig. 7, and intersect with the peripheral surface along the lines 24 (see Fig. 6), which, in the first embodiment, are disposed V inch below the plane of the top surface of the rotor.

In accordance with the present invention, the rotor is also provided with one or more notches or recesses in its periphery. Each recess opens radially outwardly and also downwardly; in other words, it is open in the periphery or on its radially outer side and it is also open at the bottom. The preferred embodiment shown in Figs. 1 to 9 includes two recesses 25 disposed directly below the two impelling vanes 21 respectively. Each of these recesses is of circular or arcuate form when viewed as in Fig. 8. The recess extends upwardly to the level of the major portion of the top surface of the rotor adjacent the periphery. The uppermost portion of the recess is disposed directly beneath the impelling vane 21, so that the top of the recess is closed by such impelling vane. As shown in Fig. 3, the rear surface of the recess is substantially vertical. It will be noted that the sides of the recess diverge downwardly, i. e., the width increases in downward direction. In the present embodiment, the recess 25 is formed on aradius of inch and it is disposed with the uppermost portion in the plane of the top surface of the rotor. The arcuate form of the recess 25 shown in Fig. 8 extends uniformly to the rear surface.

The rotor is preferably provided with four additional recesses 26. Each of these recesses has a narrow neck portion 27 at the top, which opens through the top surface of the rotor. However, it is made sufliciently narrow to permit passage only of particles that have been reduced to the small size desired. In the commercial embodiment, for example, it has a width of inch, which is less'than that of the strainer slots heretofore mentioned. The main portion of the recess 26 below the neck portion 27 is generally similar to the recess 25, being also formed on the arc of a circle and flaring downwardly. Its uppermost portion is at least as high as the surface of the inclined slot 23 at the periphery, at 24. In the first embodiment, the main portion is formed on an are having a radius of inch, and its intersection with the neck portion 27 is disposed not more than .045 inch below the plane of the top sur-. face of the rotor, so that it is above the edge 24 of the slot 23. The rear wall 28 may be, as shown in Fig. 10, inclined inwardly and downwardly at an angle to vertical to facilitate fabrication. The form of the recess 26 shown in Fig. 9 extends uniformly to the rear wall 28.

The recesses 25a and 26a of the second embodiment shown in Figs. 11 to 14 are generally similar to the recesses of the first embodiment, the principal difference being that the sides are flat instead of curved. The rear wall of the recess 25a is shown in Figs. 12 and 13 as sloping inwardly and downwardly. The sides of the recess 25a are inclined in such position that they intersect the rear wall along parallel lines as shown in Figs. 11 and 13, the peripheral surface of the rotor along lines that diverge downwardly as shown in Fig. 11, and the bottom surface of the rotor 14a along lines that diverge outwardly as shown in Fig. 13.

The sides of 'the main portion of the recess 26a are flat and diverge downwardly, each side being disposed, for example, at an angle of to vertical. The form of the recess 26a shown in Fig. 14 extends uniformly to the rear wall 28, which may be disposed in the same way as the wall 28 of the first embodiment, as shown in Fig. 10. Y

The rotor 14b of the third embodiment shown in Figs. 15, 16 and 17 has recesses 25b, which are similar to the recesses 25a of the second embodiment, except that these recesses are wider. The rotor of this embodiment does not have recesses corresponding to the recesses 26 and 26a of the other embodiments.

Operation The operation of all three embodiments is substantially the same. Food waste to be comminuted is admitted into the grinding chamber 11 through the opening in the top thereof, flow of water through such open top is established, and the motor is then energized. The rotor 14 serves to rotate the material in the chamber 11 by means of the impelling vanes 21, so that the material is rotated and thrown outwardly by centrifugal force against the shredding projections 19 and the teeth 17. As particles of sufiiciently small size are formed, they are carried away by the stream of water through the strainer slots 18 into the discharge chamber 12, from which they are carried through a fitting 29 into a series of waste pipes. This operation is well known.

When fibrous material, such as corn husks, string, and cloth tea bags, is admitted to the grinding chamber, it has been found that the fibers begin to accumulate in the gap between the periphery of the rotor and the adjacent inner surface of the teeth 17. This accumulation of fibrous material is avoided by the recesses in the periphery of the rotor of the character shown. Consider that the rotor is rotating and that material begins to become wedged in the gap between the rotor and the shredding element. As the rotor turns, one of the recesses sweeps across the wedged material. Considering first the first embodiment, this may be any one of the recesses 25 and 26. At this point, the recess provides a sudden increase in the size of the gap and therefore a sudden decrease in the force or squeeze which holds the material in the gap. As there is no appreciable force holding the material in the gap, the material is washed The slots 23 also provide an increase in the gap as one of the 'slots sweeps by, thereby freeing material that might otherwise tend to accumulate between the uppermost portion of the rotor and the shredder. Since the upper extremity of the main portion of the recess 26 is above the lower edge 24 of the slots 23, there is no point in the height of the gap between the rotor and the shredder sleeve that does not receive the effect of a sudden increase in gap size. Also, each recess 25, being closed at the top by the impeller 21 to prevent the escape of particles not ground sufliciently fine, extends the full height of the major portion of the rotor. Thus, any tendency to accumulate material in the gap is effectively overcome.

The notches 25a and 26a of the second embodiment function in substantially the same manner and produce substantially the same result. It has been found, however, that the curved form of the first embodiment provides improved performance.

The operation of the third embodiment again is sub- :stantially'the same as that of the other embodiments. 'In this case, however, due to the smaller number of recesses, the action in disposing of material that may become wedged is not as rapid.

While the invention has been shown in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What is claimed is:

1. In a food waste disposer, the combination of a shredding sleeve and a disc-like rotor disposed within said sleeve with close radial clearance between the periphery of the rotor and the inner surface of the sleeve, said sleeve having strainer slots in its inner surface adjacent the periphery of the rotor, said strainer slots being of a Width to pass the size of particle to which it is desired to comminute material, said rotor having a recess in its periphery which extends upwardly at least as high as the lowermost portion of the top surface of the rotor adjacent the periphery, said recess, throughout the major portion of its vertical extent, having a width greater than the width of said strainer slots, the Width of said recess at the top surface of the rotor being not greater than the width of said strain-er slots.

2. The combination set forth in claim 1 wherein the width of said notch gradually increases in downward direction.

3. In a food waste disposer, the combination of a shredding sleeve, 21 disc-like rotor disposed within said sleeve with close radial clearance between the periphery of the rotor and the inner surface of the sleeve, said sleeve having strainer slots in its inner surface adjacent the periphery of the rotor, said strainer slots being of a width to pass the size of particle to which it is desired to comminute material, said rotor having a projection on its upper surface adjacent its periphery and also having a recess in its periphery beneath said projection, said recess extending upwardly as high as the top surface of the rotor adjacent the periphery thereof, said recess, throughout the major portion of its vertical extent, having a width greater than the width of said strainer slots, said recess opening downwardly and radially outwardly and being closed at the top by said projection.

4. In a food waste disposer, the combination of a shredding sleeve and a disc-like rotor disposed within said sleeve with close radial clearance between the periphery of the rotor and the shredding sleeve, said sleeve having strainer slots in its inner surface adjacent the periphery of the rotor, said rotor having a recess in its periphery which opens downwardly and radially outwardly, the width of said recess from the bottom of the periphery and for the major portion. of the height of the periphery being greater than the Width of the strainer slots, and the width of said recess at the top surface of the rotor being not greaterthan the width of said strainer slots.

References Cited in the file of this patent Swisher Feb. 16, 1954 

